Recoverable prepreg, solidified sheet and copper-clad plate for printed circuit board and preparation and recovery methods thereof
Technical Field
The invention relates to the technical field of epoxy resin composite materials, in particular to a recyclable epoxy resin composite material.
Background
The main raw materials of the copper-clad plate composite material comprise copper foil, reinforced fiber cloth, epoxy resin, a curing agent, an accelerator, a solvent, a filler and the like, and are closely related to the technological property, the processing property and the comprehensive property of a final product in the production process of the copper-clad plate. The laminated board with metal copper foil coated on one or two surfaces of the substrate is called copper clad board, mainly used for manufacturing printed circuit board, widely applied to products such as communication, mobile communication, computer, instrument and meter, digital television, numerical control sound, satellite, radar and the like, and also applied to the new product fields such as solar battery, LED illumination, LED backlight source, flat panel display, automobile electronic and the like in recent years. In the electronic whole machine product, the copper-clad plate plays three roles of element load, circuit interconnection and circuit insulation.
The epoxy resin is widely applied to the copper-clad plate due to excellent processing performance before curing, excellent adhesive force after curing, mechanical strength, heat dispersibility, electrical performance, chemical resistance and the like. In addition, the high density, three-dimensional network structure of the cured epoxy resin makes it an extremely durable and hard material that can withstand a wide range of environmental conditions. At the same time, the crosslinked network structure of the cured epoxy resin makes its removal, recycling and reuse particularly difficult. In essence, the crosslinking reaction which normally occurs with compounding polyamines with epoxy resins is irreversible, and therefore, this substance cannot be re-melted, cannot be re-shaped without damage, and cannot be easily dissolved.
The thermosetting epoxy resin, the copper foil and the fiber are combined to prepare a copper-clad plate and can be applied to the field of Printed Circuit Boards (PCBs), and the PCB manufacturing process flow generally goes through the processes of film plate making, pattern transfer, chemical etching, via hole and copper foil treatment, soldering aid, solder resist and the like. The cured epoxy resin is difficult to decompose and melt, and accordingly, the epoxy resin-based circuit board is inconvenient to recycle.
The recovery processing technology of waste printed circuit boards at home and abroad mainly comprises three types: one is a wet processing technique. Including acid pickling, corrosion, etc.; second, the pyrogenic process treatment technology, including burning, cracking, direct smelting, etc.; and thirdly, a physical mechanical treatment technology comprising the working procedures of crushing, sorting and the like. Generally, the methods have limitations in different degrees, the treatment scale of the pyrogenic process technology is the largest, the recovery rate of the wet process technology to metal is higher, but the wet process and the pyrogenic process treatment technologies have serious environmental pollution and large environmental protection cost investment; the physical mechanical treatment method is low in investment and capable of recovering metals, but cannot realize recovery of fibers and resins. Therefore, the method for recycling the waste materials, which is environmentally friendly, effective and feasible, is still a problem to be solved in the field of materials.
Disclosure of Invention
Aiming at the problems in the prior art, the applicant provides a recyclable copper-clad plate for a printed circuit board and a preparation and recycling method thereof. The copper-clad plate prepared by the invention can reach various performance indexes and is easy to recover, and the recovery method has the advantages of mild reaction conditions, economy, easy control and the like.
The technical scheme of the invention is as follows:
the applicant provides a recyclable prepreg and a recyclable prepreg for a printed circuit board, which comprise a degradable epoxy resin matrix and a reinforcing material.
The applicant also provides a recyclable copper-clad plate for a printed circuit board, which comprises a copper foil and a recyclable prepreg. The recyclable copper-clad plate is a double-layer plate or a multilayer plate and is prepared by laminating a recyclable prepreg and a copper foil.
The degradable epoxy resin matrix comprises epoxy resin and a degradable curing agent.
The degradable curing agent is one or more of the degradable curing agents with the following molecular structure general formula:
(1)
wherein,
r1 is one of a hydrogen atom, alkyl group, cycloalkyl group, heterocyclic group, heterocycloalkyl group, alkenyl group, cycloalkenyl group, aryl group, heteroaryl group, alkylheteroalkyl group, alkynyl group, hydrocarbylene group, hydrocarbyleneheteroalkylene group, alkenylene group, hydrocarbyleneheteroalkylene group, alkynylene group, or hydrocarbyleneheteroalkylene group;
r2 is one of a hydrogen atom, alkyl group, cycloalkyl group, heterocyclic group, heterocycloalkyl group, alkenyl group, cycloalkenyl group, aryl group, heteroaryl group, alkylheteroalkyl group, alkynyl group, hydrocarbylene group, hydrocarbyleneheteroalkylene group, alkenylene group, hydrocarbyleneheteroalkylene group, alkynylene group, or hydrocarbyleneheteroalkylene group;
r1 and R2 may be the same or different;
r1 and R2 may also be in the same ring structure with the common adjacent carbon atom;
a is one of an arylidene group, a hydrocarbylidene arylidene group, an alkenylidene arylidene group, an alkynylidene arylidene group, a heteroaromatic group, a hydrocarbylidene heteroaromatic group, an alkenylidene heteroaromatic group, and an alkynylidene heteroaromatic group;
b is one of an arylidene group, a hydrocarbylidene arylidene group, an alkenylidene arylidene group, an alkynylidene arylidene group, a heteroaromatic group, a hydrocarbylidene heteroaromatic group, an alkenylidene heteroaromatic group and an alkynylidene heteroaromatic group;
a and B may be the same or different;
r3 is
R4 is
R3 and R4 may be the same or different;
r5 is one of hydrogen atom, alkyl, cycloalkyl, heterocyclic group, heterocyclic alkyl, alkenyl, cycloalkenyl, aryl, heteroaryl, alkoxyalkyl or alkynyl;
r6 is one of hydrogen atom, alkyl, cycloalkyl, heterocyclic group, heterocyclic alkyl, alkenyl, cycloalkenyl, aryl, heteroaryl, alkoxyalkyl or alkynyl;
r5 and R6 may be the same or different;
Xn-is one of C1-C10 aliphatic carboxylate anions, C1-C10 alicyclic carboxylate anions, aromatic carboxylate anions and heterocyclic aromatic carboxylate anions;
n is 1, 2 or 3;
m is 0.1 to 3;
y is one of Lewis acids;
(2)
wherein,
p1 is one of a hydrogen atom, an alkyl group, a cycloalkyl group, a heterocyclic group, a heterocycloalkyl group, an alkenyl group, a cycloalkenyl group, an aryl group, a heteroaryl group, an alkylheteroalkyl group, an alkynyl group, a hydrocarbylene group, a hydrocarbyleneheteroalkylene group, an alkenylene group, a hydrocarbyleneheteroalkylene group, an alkynylene group, or a hydrocarbyleneheteroalkynylene group;
p2 is one of a hydrogen atom, an alkyl group, a cycloalkyl group, a heterocyclic group, a heterocycloalkyl group, an alkenyl group, a cycloalkenyl group, an aryl group, a heteroaryl group, an alkylheteroalkyl group, an alkynyl group, a hydrocarbylene group, a hydrocarbyleneheteroalkylene group, an alkenylene group, a hydrocarbyleneheteroalkylene group, an alkynylene group, or a hydrocarbyleneheteroalkynylene group;
p1 and P2 may be the same or different;
p1 and P2 may also be in the same ring structure with the common adjacent carbon atom;
c is alkylene, hydrocarbylene heteroalkylene, alkenylene heteroalkenylene, hydrocarbylene heteroalkenylene, alkynylene, cycloalkylene, hydrocarbylene cycloalkylene alkylene, alkenylene cycloalkylene, hydrocarbylene cycloalkylene alkenylene, alkynylene cycloalkylene alkynylene, heterocyclic alkylene, hydrocarbylene heterocyclic alkylene, alkenylene heterocyclic alkylene, hydrocarbylene heterocyclic alkylene, alkynylene heterocyclic alkylene, alkenylene cycloalkylene, cycloalkenylene alkenylene, heterocyclic alkylene, heterocyclylene alkylene, cycloalkylene, heterocyclylene, cycloalkenylene, alkenylene, cycloalkenylene alkenylene, alkenylene, heterocyclylene alkenylene, alkynylene cycloalkenylene, heterocyclylene alkenylene, heterocyclylene alkylene heterocyclylene, heterocyclylene alkylene, cycloalkylene, alkenylene, heterocyclylene, cycloalkylene, cycloalkenylene, cycloalkylene, heterocyclylene, alkynylene, heterocyclylene, cycloalkenylene, cycloalkylene, cycloalkenylene, One of a hydrocarbylene heterocycloalkenylene, an arylene, a hydrocarbylene arylene, a heteroarylene, a hydrocarbylene heteroarylene, and a hydrocarbylene heteroarylene alkynylene;
d is alkylene, hydrocarbylene heteroalkylene, alkenylene heteroalkenylene, hydrocarbylene heteroalkenylene, alkynylene, cycloalkylene, hydrocarbylene cycloalkylene, alkenylene cycloalkylene, hydrocarbylene cycloalkylene alkenylene, alkynylene cycloalkylene alkynylene, heterocyclic alkylene, hydrocarbylene heterocyclic alkylene, alkenylene heterocyclic alkylene, hydrocarbylene heterocyclic cycloalkylene, alkynylene heterocyclic alkylene, cycloalkenylene, cycloalkylene alkylene, alkenylene cycloalkenylene, alkenylene, cycloalkenylene alkenylene, alkynylene alkylene heterocyclic alkylene, cycloalkenylene alkylene, alkenylene heterocyclenylene alkylene, alkynylene cycloalkenylene alkenylene, heterocycloalkenylene alkenylene, alkenylene heterocycloalkenylene, alkenylene, heterocycloalkenylene, alkynylene, heterocycloalkenylene, cycloalkenylene, heterocycloalkenylene, cycloalkenylene, cycloalkenyl, One of a hydrocarbylene heterocycloalkenylene, an arylene, a hydrocarbylene arylene, a heteroarylene, a hydrocarbylene heteroarylene, and a hydrocarbylene heteroarylene alkynylene;
c and D may be the same or different;
(3)
wherein,
Q1、Q2、Q3、Q4、Q51and Q6Can be respectively hydrogen atom, alkyl, cycloalkyl, heterocyclic radical, heterocyclic alkyl, alkenyl, cycloalkenyl, alkynyl, aryl, heteroaryl, aryleneHydrocarbyloxyalkyl, hydrocarbyleneoxycycloalkyl, hydrocarbyleneoxinyl, hydrocarbyleneoxacycloalkyl, hydrocarbyleneoxyalkenyl, hydrocarbyleneoxycycloalkenyl, hydrocarbyleneoxyaryl, cycloalkyleneoxyalkyl, cycloalkyleneoxycycloalkyl, cycloalkyleneoxyalkenyl, cycloalkyleneoxycycloalkenyl, cycloalkyleneoxyalkenyl, cycloalkyleneoxyaryl, one of a heterocycloalkyleneoxyalkyl group, a heterocycloalkyleneoxycycloalkyl group, a heterocycloalkyleneoxetanyl group, a heterocycloalkyleneoxycycloalkyl group, a heterocycloalkyleneoxyalkylene group, a heterocycloalkyleneoxycycloalkenyl group, a heterocycloalkyleneoxoaryl group, an aryloxyalkyl group, an aryloxyalkenyl group, an aryloxyalkyl group, and an aryloxyalkyl group;
Q1、Q22、Q3、Q4、Q5and Q6May be the same or different;
Q5and Q6May or may not be in the same ring structure as the commonly adjacent carbon atom;
Q1and E may or may not be in the same ring structure as the commonly adjacent carbon atom;
Q4and F may or may not be in the same ring structure as the commonly adjacent carbon atom;
e and F may be alkylene, hydrocarbylene heteroalkylene, alkenylene heteroalkenylene, hydrocarbylene heteroalkenylene, alkynylene, cycloalkylene, hydrocarbylene cycloalkylene alkylene, alkenylene cycloalkylene, alkynylene cycloalkylene alkynylene, heterocyclic alkylene, hydrocarbylene heterocyclic alkylene, alkenylene heterocyclic alkylene, hydrocarbylene heterocyclic alkylene, alkynylene heterocyclic alkylene, cycloalkenylene, hydrocarbylene cycloalkenylene alkylene, alkenylene cycloalkenylene, alkenylene, alkynylene cycloalkenylene alkylene, cycloalkylene cycloalkenylene alkylene, alkynylene cycloalkenylene alkylene, alkenylene heterocyclylene alkylene, alkenylene cycloalkenylene, alkynylene cycloalkenylene alkenylene, heterocyclylene alkylene alkenylene, heterocyclylene alkylene heterocyclylene, alkynylene alkylene heterocyclylene alkylene alkenylene cycloalkenylene alkenylene, alkynylene, heterocyclylene alkylene alkenylene cycloalkenylene alkenylene, One of alkenylene heterocycloalkenylene, alkynylene heterocycloalkenylene alkynylene, arylene, hydrocarbylene arylene, alkenylene arylene, hydrocarbylene arylene, alkynylene arylene, heteroarylene, hydrocarbylene heteroarylene, alkenylene heteroarylene, hydrocarbylene heteroarylene, alkynylene heteroarylene, carbonyl, and thiocarbonyl;
e and F may be the same or different;
(4)
wherein,
n is greater than 1;
W1is alkylene, hydrocarbylene heteroalkylene, alkenylene heteroalkenylene, hydrocarbylene heteroalkenylene, alkynylene, cycloalkylene, hydrocarbylene cycloalkylene alkylene, alkenylene cycloalkylene, hydrocarbylene cycloalkylene alkenylene, alkynylene cycloalkylene alkynylene, heterocyclic alkylene, hydrocarbylene heterocyclic alkylene, alkenylene heterocyclic alkylene, hydrocarbylene heterocyclic cycloalkylene, alkynylene heterocyclic alkylene, cycloalkenylene, hydrocarbylene cycloalkenylene alkylene, alkenylene cycloalkenylene, hydrocarbylene cycloalkenylene alkenylene, alkynylene cycloalkenylene, alkynylene, heterocycloalkenylene alkenylene, alkynylene cycloalkenylene alkenylene, heterocycloalkenylene alkenylene, heterocycloalkenylene alkenyleneOne of a group, a hydrocarbylene heterocycloalkenylene group, a alkenylene heterocycloalkenylene group, a hydrocarbylene heterocycloalkenylene group, an alkynylene heterocycloalkenylene alkynylene group, an arylene group, a hydrocarbylene arylene group, an alkenylene arylene group, a hydrocarbylene arylene group, an alkynylene arylene group, a heteroarylene group, a hydrocarbylene heteroarylene group, an alkenylene heteroarylene group, a hydrocarbylene heteroarylene group, a alkynylene heteroarylene group, an alkynylene heteroarylene group, or alkynylene heteroarylene group;
each W2Is one of a hydrogen atom, an alkyl group, a cycloalkyl group, a heterocyclic group, a heterocycloalkyl group, an alkenyl group, a cycloalkenyl group, an aryl group, a heteroaryl group, an alkylheteroalkyl group, an alkynyl group, a hydrocarbylene group, a hydrocarbyleneheteroalkylene group, an alkenylene group, a hydrocarbyleneheteroalkylene group, an alkynylene group, or a hydrocarbyleneheteroalkynylene group.
The epoxy resin of the recyclable prepreg, the recyclable cured sheet and the recyclable copper-clad plate is at least one of glycidyl ether type epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, alicyclic epoxy resin, aliphatic epoxy resin and novolac epoxy resin.
The degradable epoxy resin matrix of the recyclable prepreg, the recyclable cured sheet and the recyclable copper-clad plate also comprises auxiliary materials. The auxiliary material is at least one of an accelerator, a diluent, a toughening agent, a thickening agent, an adhesion promoter, a whitening agent, a pigment, an addition component, a coupling agent, a filler, a thixotropic agent and an antioxidant.
The reinforcing material of the recyclable prepreg, the recyclable curing sheet and the recyclable copper-clad plate is a fiber material or a non-fiber material. The fiber material is at least one of glass fiber, carbon fiber, natural fiber and chemical fiber; the non-fibrous material is at least one of carbon nanotubes, carbon black, metal nanoparticles, organic nanoparticles, iron oxide, and boron nitride.
The applicant provides a recyclable prepreg and a preparation method of the recyclable prepreg, which comprises at least one of a solvent method and a non-solvent method. The solvent method is to prepare a resin prepreg through degradable epoxy resin glue solution containing a solvent. The solvent is acetone, propyl acetate, methyl ethyl ketone, methyl isobutyl ketone, toluene, N-dimethylformamide, N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide or xylene.
The non-solvent method is to prepare a resin prepreg through a solvent-free degradable epoxy resin glue solution.
The first method for preparing the recyclable copper-clad plate from the recyclable prepreg and the recyclable curing sheet comprises the following specific preparation steps:
(1) dissolving 45-70 wt% of epoxy resin and 5-25 wt% of degradable curing agent in a solvent, uniformly mixing, adding 15-30 wt% of auxiliary material, and mixing to prepare a degradable epoxy resin glue solution with a solid content of 45-80%;
(2) coating the degradable epoxy resin glue solution on a reinforcing material, and baking for 200-800 sec at 150-200 ℃ to obtain a prepreg;
(3) and (3) orderly overlapping at least 1 prepreg, placing the two sides covered with copper foils into a hot press, and carrying out hot pressing and curing for 60-120 min under the conditions of 2-6 Mpa pressure and 150-200 ℃ to obtain the recyclable copper-clad plate.
The second method for preparing the recyclable copper-clad plate from the recyclable prepreg and the recyclable curing sheet comprises the following specific preparation steps:
(1) melting and uniformly mixing 45-70 wt% of epoxy resin at 60-120 ℃, adding 5-25 wt% of degradable curing agent at 60-100 ℃, uniformly mixing, adding 15-30 wt% of auxiliary material, and mixing to prepare a degradable epoxy resin adhesive;
(2) coating the degradable epoxy resin adhesive on a reinforcing material at the temperature of 60-100 ℃, and baking for about 200-800 sec at the temperature of 150-200 ℃ to obtain a prepreg;
(3) and (3) orderly overlapping at least 1 prepreg, placing the two sides covered with copper foils into a hot press, and carrying out hot pressing and curing for 60-120 min under the conditions of 2-6 Mpa pressure and 150-200 ℃ to obtain the recyclable copper-clad plate.
The invention also provides a method for recovering the recoverable prepreg, the recoverable solidified sheet and the recoverable copper-clad plate, which comprises a step of degrading the degradable epoxy resin matrix by using acid and a solvent.
The degradation is carried out under heating.
The acid is at least one of hydrochloric acid, hydrobromic acid, hydrofluoric acid, acetic acid, trifluoroacetic acid, lactic acid, formic acid, propionic acid, citric acid, methanesulfonic acid, p-toluenesulfonic acid, nitric acid, sulfuric acid, sulfurous acid, phosphoric acid, perchloric acid, benzoic acid, salicylic acid and phthalic acid.
The solvent is at least one of methanol, ethanol, glycol, propanol, isopropanol, butanol, isobutanol, tert-butanol, pentanol, hexanol, heptanol, octanol, nonanol, benzyl alcohol, phenethyl alcohol, p-dimethylolbenzene, m-dimethylolbenzene, o-dimethylolbenzene, p-dihydroxyethylbenzene, m-dihydroxyethylbenzene, o-dihydroxyethylbenzene, water, N-dimethylformamide, N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, tetrahydrofuran, methyltetrahydrofuran, glycerol, dioxane.
The concentration of the acid is 0.1-90 wt%. Preferably, the concentration of the acid is 10 to 20 wt%.
The heating temperature is 15-400 ℃, and the heating time is 1-120 hours. Preferably, the heating temperature is 80-120 ℃, and the heating time is 4-8 hours.
The recovery process further comprises a step of recovering the degradation products by neutralization, filtration and/or precipitation.
The degradable epoxy resin matrix, namely the curing agent and epoxy resin system, can also comprise auxiliary materials, and the degradable cross-linked polymer generated by polymerization can be combined with glass fiber cloth, glass fiber paper, paper and synthetic fiber to prepare the recyclable copper-clad plate.
The copper-clad plate of the invention has the following recovery principle: the copper clad laminate with copper foil stripped is soaked in a hot acid and solvent recovery solution, firstly, an epoxy resin matrix is decomposed, then, a recovery reinforcing material is separated, and finally, a product of epoxy resin degradation is recovered through neutralization of alkali liquor. Under such conditions, the epoxy resin matrix can be decomposed because its crosslinked structure is acid-sensitive, in which acetal groups can undergo bond cleavage, resulting in decomposition of the crosslinked structure of the epoxy resin matrix into a non-crosslinked polymer (e.g., a thermoplastic epoxy resin) that can be dissolved in an organic solvent. When the epoxy resin matrix is fully dissolved, the reinforcing material can be taken out of the solution, and the solution is neutralized by alkali, settled and subjected to solid-liquid separation to recover the epoxy resin matrix degradation product. Both the recycled reinforcement material and the non-crosslinked polymer can be separated, recycled and reused.
The beneficial technical effects of the invention are as follows:
the invention takes the degradable epoxy resin matrix as the raw material to prepare the recyclable copper-clad plate, and can be applied to the preparation of printed circuit boards. Under certain conditions, the printed circuit board can be recycled, and the precious metal, the reinforcing material and the epoxy resin matrix degradation product can be separated and recycled.
The present invention prepares copper clad laminate with degradable epoxy resin matrix and uses it in printed circuit board, and can degrade under mild condition without special condition, and the copper foil, plastic component and reinforcing material in the printed circuit board can be recovered, so that the recovery is more efficient.
The manufacturing process flow of the PCB needs to go through the processes of chemical etching (acidity and alkalinity) and the like, and the copper-clad plate prepared by the invention is degraded under the acidic condition, but is not degraded in the chemical etching (acidity and alkalinity) process of the PCB; in addition, the degradation recovery method can be carried out under relatively mild reaction conditions, is economical and easy to control, and both the reinforcing material and the epoxy resin matrix degradation product can be separated and recovered.
The epoxy resin condensate (namely the degradable cross-linked polymer generated by polymerizing the degradable curing agent and the epoxy resin system) can be degraded to form the thermoplastic epoxy resin polymer, only a small amount of acetal groups are lost in the degradation process, the quality recovery rate of the thermoplastic epoxy resin polymer is high, and the polymer can be processed and used in industrial application.
The mass recovery rate of the epoxy resin condensate and the reinforcing material is more than 96 percent; more than 95% of the reinforced materials (such as glass fiber) in the circuit board composite material can be recovered, the recovered reinforced materials keep most of the original texture and mechanical properties, are stable under the acidic recovery condition, have clean surfaces and basically have no defects, and can be reused in new composite materials; the recovered epoxy resin polymer degradation products can be processed for use on plastic articles.
Drawings
FIG. 1 is a schematic diagram of a partially degraded recyclable copper clad laminate as performed in example 19;
FIG. 2 is a schematic diagram of a 4-layer PCB sample prepared in example 22.
Detailed Description
Example 1: preparation of degradable bromine-containing flame-retardant FR-4 copper-clad plate sample
(1) Preparation of curing agent A:
dissolving 13.4 g of p-benzaldehyde in 370 g of ethanol, weighing 20g of ethanol, putting into a reaction bottle, adding 14.7 g of 85% hydrazine hydrate, stirring, dropwise adding the ethanol solution of p-benzaldehyde in a room-temperature water bath for about 1 hour, and reacting at room temperature for 5-6 hours after dropwise adding. After the reaction, the mixture was filtered, and the filter cake was washed with ethanol and dried to obtain 13.9 g of a yellow solid.
The melting point is 158-166 DEG C
1H-NMR(400MHz,d6-DMSO):7.67(s,2H),7.42(s,4H),6.76(s,4H)。
(2) Preparing degradable epoxy resin glue solution: weighing 40g of bisphenol A type liquid epoxy resin E54(EEW 0.53-0.54 eq./100g), 28g of bisphenol A type solid epoxy resin E21(EEW 0.20-0.22 eq./100g), 132g of low-bromine epoxy resin (Br content is about 20%, EEW 0.23-0.24 eq./100g) and 23.62g A curing agent (AEW2.47N-H eq./100g), adding a proper amount of DMF as a solvent, and dissolving and mixing uniformly; then 0.75g of the silane coupling agent KH560 and 74.5g of molten SiO were added2Micro powder (D505-10 μm), and stirring for 30min by using a high-speed dispersion machine to obtain a glue solution with the solid content S/C of about 60%; gel time S/G of gel liquid at 171 ℃: 300-350 sec.
(3) Preparation of resin prepreg: soaking 7628 glass cloth in the prepared glue solution, baking for 10min at 150 ℃ in an oven to obtain a prepreg with the glue content R/C being about 45%, wherein the gel time P/G of the prepreg glue powder at 171 ℃ is as follows: 150-170 sec.
(4) Preparing a copper-clad plate: and (3) overlapping more than 5 prepared resin prepregs, covering copper foils (1OzHTE copper foils) on two sides, pressing for 60min at 170 ℃ in a hot press, and naturally cooling to obtain the copper-clad plate with the thickness of about 1.0 mm. The performance test method of the copper-clad plate is shown in table 1, and the main performance of the copper-clad plate obtained in the embodiment is shown in table 2. In the table, all the properties of copper-clad plate samples meet the requirements of IPC4101/126, and the use requirements of common FR-4 copper-clad plates are met.
Example 2: preparation of degradable bromine-containing flame-retardant FR-4 copper-clad plate sample
(1) Preparation of curing agent B:
the first step is as follows: sequentially putting 800 g of 2-chloroethanol, 164 g of paraformaldehyde, 4.8 g of p-toluenesulfonic acid and 346 g of toluene into a 2L reaction bottle, heating, refluxing and water dividing for 6h, recovering the toluene under reduced pressure after the reaction is finished, distilling the residue under reduced pressure, and collecting fractions at 71-72 ℃/70Pa to obtain about 739 g of bis (2-chloroethoxy) methane.
The second step is that: putting 2200 g of DMF into a 10L reaction bottle, adding 569 g of bis (2-chloroethoxy) methane, 1000 g of methyl paraben and 300 g of caustic soda flakes in turn under stirring, heating and refluxing for 16 hours, cooling to 60 ℃ after the reaction is finished, concentrating and recovering DMF, adding water into residues to separate out white solid, and drying to obtain 960 g of intermediate.
The third step: 3600 g of ethanol, 960 g of the second-step intermediate and 900 g of 85% hydrazine hydrate are sequentially put into a 10L reaction bottle, the temperature is raised, the mixture is stirred and refluxed for 16 hours, after the reaction is finished, crystals are separated out by cooling, the crystals are filtered, and the solids are recrystallized by ethanol to obtain 389 g of curing agent B.
1H-NMR(400MHz,d6-DMSO):9.63(s,2H),7.79(d,4H),6.98(d,4H),4.76(s,2H),4.45(s,4H),4.17(t,4H),3.84(t,4H);
LC/MS(M+H+):405。
(2) Preparing degradable epoxy resin glue solution: weighing 40g of bisphenol A type liquid epoxy resin E54(EEW 0.53-0.54 eq./100g), 28g of bisphenol A type solid epoxy resin E21(EEW 0.20-0.22 eq./100g), 132g of low bromine epoxy resin (Br content about 20%, EEW 0.23-0.24 eq./100g) and 58.92g B curing agent (AEW0.99N-H eq./100g), and adding a proper amount ofMethyl ethyl ketone is used as a solvent, and the methyl ethyl ketone and the solvent are dissolved and mixed uniformly; then 0.86g of the silane coupling agent KH560 and 86.3g of molten SiO were added2Micro powder (D505-10 μm), and stirring for 30min by using a high-speed dispersion machine to obtain a glue solution with the solid content S/C of about 60%; gel time S/G of gel liquid at 171 ℃: 280-320 sec.
(3) Preparation of resin prepreg: soaking 7628 glass cloth in the prepared glue solution, baking for 10min at 150 ℃ in an oven to obtain a prepreg with the glue content R/C being about 45%, wherein the gel time P/G of the prepreg glue powder at 171 ℃ is as follows: 140-160 sec.
(4) Preparing a copper-clad plate: and (3) overlapping more than 5 prepared resin prepregs, covering copper foils (1OzHTE copper foils) on two sides, pressing for 60min at 170 ℃ in a hot press, and naturally cooling to obtain the copper-clad plate with the thickness of about 1.0 mm. The performance test method of the copper-clad plate is shown in table 1, and the main performance of the copper-clad plate obtained in the embodiment is shown in table 2. In the table, all the performances of the copper-clad plate all meet the requirements of IPC4101/126, and the use requirements of the common FR-4 copper-clad plate are met.
Example 3: preparation of degradable bromine-containing flame-retardant FR-4 copper-clad plate sample
(1) Preparation of curing agent C:
in a 250 ml three-neck round bottom flask equipped with a condenser, 10g of methyl p-hydroxybenzoate, 6.8 g of dibromomethane and 3.9 g of sodium hydroxide are dissolved in 25 ml of N, N-Dimethylformamide (DMF), the mixture is heated and refluxed for 5 hours, then cooled to room temperature, the mother liquor is concentrated, water is added to separate out a solid, and the solid is filtered and dried to obtain 3g of an intermediate.
Dissolving the intermediate in 10 ml ethanol in a 250 ml three-neck round-bottom flask with a condenser, adding 1.4 g hydrazine hydrate, heating to 78 deg.C, refluxing for 2 hr, cooling to below 5 deg.C, separating out solid, suction filtering the separated out solid, and washing with ethanol to obtain 1.5 g white solid product.
Melting point: 248-249 deg.C
1H-NMR(400MHz,d6-DMSO):9.66(s,2H),7.81(d,4H),7.14(d,4H),5.96(s,2H),4.45(s,4H);
LC/MS(M+H+):317。
(2) Preparing degradable epoxy resin glue solution: weighing 40g of bisphenol A type liquid epoxy resin E54(EEW 0.53-0.54 eq./100g), 28g of bisphenol A type solid epoxy resin E21(EEW 0.20-0.22 eq./100g), 132g of low-bromine epoxy resin (Br content is about 20%, EEW 0.23-0.24 eq./100g) and 46.15g C curing agent (AEW1.26N-H eq./100g), adding a proper amount of N-methylpyrrolidone as a solvent, and dissolving and mixing uniformly; then 0.82g of silane coupling agent KH560 and 82.0g of molten SiO were added2Micro powder (D505-10 mu m), adding 4.92g of UR-200 curing accelerator, and stirring for 30min by using a high-speed dispersion machine to obtain a glue solution with the solid content S/C being about 60%; gel time S/G of gel liquid at 171 ℃: 260-300 sec.
(3) Preparation of resin prepreg: soaking 7628 glass cloth in the prepared glue solution, baking for 10min at 150 ℃ in an oven to obtain a prepreg with the glue content R/C being about 45%, wherein the gel time P/G of the prepreg glue powder at 171 ℃ is as follows: 130-150 sec.
(4) Preparing a copper-clad plate: and (3) overlapping more than 5 prepared resin prepregs, covering copper foils (1OzHTE copper foils) on two sides, pressing for 60min at 170 ℃ in a hot press, and naturally cooling to obtain the copper-clad plate with the thickness of about 1.0 mm. The performance test method of the copper-clad plate is shown in table 1, and the main performance of the copper-clad plate obtained in the embodiment is shown in table 2. In the table, all the performances of the copper-clad plate all meet the requirements of IPC4101/126, and the use requirements of the common FR-4 copper-clad plate are met.
Example 4: preparation of degradable bromine-containing flame-retardant FR-4 copper-clad plate sample
(1) Can be used forPreparing a degraded epoxy resin glue solution: weighing 40g of bisphenol A type liquid epoxy resin E54(EEW 0.53-0.54 eq./100g), 10g of trifunctional epoxy resin XY636(EEW 0.69-0.71 eq./100g), 70g of low-bromine epoxy resin (Br content is about 20%, EEW 0.23-0.24 eq./100g), 80g of isocyanate modified epoxy (EEW 0.34-0.40 eq./100g) and 46.15g B curing agent (AEW0.99N-H eq./100g), adding a proper amount of acetone as a solvent, and dissolving and mixing uniformly; then 0.92g of the silane coupling agent KH560 and 91.7g of molten SiO were added2Micro powder (D505-10 mu m), adding 33g of tetrabromobisphenol A serving as a flame retardant, and stirring for 30min by using a high-speed dispersion machine to prepare a glue solution with the solid content S/C being about 60%; gel time S/G of gel liquid at 171 ℃: 280-320 sec.
(2) Preparation of resin prepreg: soaking 7628 glass cloth in the prepared glue solution, baking for 10min at 150 ℃ in an oven to obtain a prepreg with the glue content R/C being about 45%, wherein the gel time P/G of the prepreg glue powder at 171 ℃ is as follows: 140-160 sec.
(3) Preparing a copper-clad plate: and (3) overlapping more than 5 prepared resin prepregs, covering copper foils (1OzHTE copper foils) on two sides, pressing for 60min at 190 ℃ in a hot press, and naturally cooling to obtain the copper-clad plate with the thickness of about 1.0 mm. The performance test method of the copper-clad plate is shown in table 1, and the main performance of the copper-clad plate obtained in the embodiment is shown in table 2. In the table, all the performances of the copper-clad plate meet the requirements of IPC4101/128 and meet the use requirements of a Hi-Tg FR-4 copper-clad plate.
Example 5: preparation of degradable bromine-containing flame-retardant FR-4 copper-clad plate sample
(1) Preparing degradable epoxy resin glue solution: weighing 40g of bisphenol A type liquid epoxy resin E54(EEW 0.53-0.54 eq./100g), 10g of trifunctional epoxy resin XY636(EEW 0.69-0.71 eq./100g), 70g of low-bromine epoxy resin (Br content is about 20%, EEW 0.23-0.24 eq./100g), 80g of isocyanate modified epoxy (EEW 0.34-0.40 eq./100g) and 58.9g C curing agent (AEW1.26N-H eq./100g), adding a proper amount of DMF as a solvent, and dissolving and mixing uniformly; then 0.86g of a silane coupling agent KH560 and86.3g of fused SiO2Micro powder (D505-10 mu m), adding 31g of tetrabromobisphenol A serving as a flame retardant and 5.17g of UR-200 curing agent, and stirring for 30min by adopting a high-speed dispersion machine to prepare a glue solution with the solid content S/C being about 60%; gel time S/G of gel liquid at 171 ℃: 300-340 sec.
(2) Preparation of resin prepreg: soaking 7628 glass cloth in the prepared glue solution, baking for 10min at 150 ℃ in an oven to obtain a prepreg with the glue content R/C being about 45%, wherein the gel time P/G of the prepreg glue powder at 171 ℃ is as follows: 150-170 sec.
(3) Preparing a copper-clad plate: and (3) overlapping more than 5 prepared resin prepregs, covering copper foils (1OzHTE copper foils) on two sides, pressing for 60min at 190 ℃ in a hot press, and naturally cooling to obtain the copper-clad plate with the thickness of about 1.0 mm. The performance test method of the copper-clad plate is shown in table 1, and the main performance of the copper-clad plate obtained in the embodiment is shown in table 2. In the table, all the performances of the copper-clad plate meet the requirements of IPC4101/128 and meet the use requirements of a Hi-Tg FR-4 copper-clad plate.
Example 6: preparation of degradable halogen-free flame-retardant FR-4 copper-clad plate sample
(1) Preparing degradable epoxy resin glue solution: weighing 70g of bisphenol A type liquid epoxy resin E54(EEW 0.53-0.54 eq./100g), 50g of bisphenol A type solid epoxy resin E21(EEW 0.20-0.22 eq./100g), 80g of phosphorus-containing epoxy resin (P content is 2.5%, EEW 0.22-0.24 eq./100g) and 26.78g A curing agent (AEW2.47N-H eq./100g), adding a proper amount of xylene as a solvent, and dissolving and mixing uniformly; then 0.76g of silane coupling agent KH560 and 75.6g of molten SiO were added2Micro powder (D505-10 μm), and stirring for 30min by using a high-speed dispersion machine to obtain a glue solution with the solid content S/C of about 60%; gel time S/G of gel liquid at 171 ℃: 300-340 sec.
(2) Preparation of resin prepreg: soaking 7628 glass cloth in the prepared glue solution, baking for 10min at 150 ℃ in an oven to obtain a prepreg with the glue content R/C being about 45%, wherein the gel time P/G of the prepreg glue powder at 171 ℃ is as follows: 150-170 sec.
(3) Preparing a copper-clad plate: and (3) overlapping more than 5 prepared resin prepregs, covering copper foils (1OzHTE copper foils) on two sides, pressing for 60min at 170 ℃ in a hot press, and naturally cooling to obtain the copper-clad plate with the thickness of about 1.0 mm. The performance test method of the copper-clad plate is shown in table 1, and the main performance of the copper-clad plate obtained in the embodiment is shown in table 3. In the table, all the performances of the copper-clad plate meet the requirements of IPC4101/126, and the use requirements of the halogen-free flame-retardant FR-4 copper-clad plate are met.
Example 7: preparation of degradable halogen-free flame-retardant FR-4 copper-clad plate sample
(1) Preparing degradable epoxy resin glue solution: weighing 20g of bisphenol A type liquid epoxy resin E54(EEW 0.53-0.54 eq./100g), 10g of trifunctional epoxy resin XY636(EEW 0.69-0.71 eq./100g), 80g of isocyanate modified epoxy (EEW 0.34-0.40 eq./100g), 90g of phosphorus-containing epoxy resin (P content is 2%, EEW 0.37-0.42 eq./100g) and 83.4g B curing agent (AEW0.99N-H eq./100g), adding a proper amount of toluene as a solvent, and dissolving and mixing uniformly; then 0.94g of silane coupling agent KH560 and 94.4g of molten SiO were added2Adding 22.6g of SPB-100 phosphazene flame retardant into the micro powder (D505-10 mu m), and stirring for 30min by using a high-speed dispersion machine to obtain a glue solution with the solid content S/C of about 60%; gel time S/G of gel liquid at 171 ℃: 260-300 sec.
(2) Preparation of resin prepreg: soaking 7628 glass cloth in the prepared glue solution, baking for 10min at 150 ℃ in an oven to obtain a prepreg with the glue content R/C being about 45%, wherein the gel time P/G of the prepreg glue powder at 171 ℃ is as follows: 130-150 sec.
(3) Preparing a copper-clad plate: and (3) overlapping more than 5 prepared resin prepregs, covering copper foils (1OzHTE copper foils) on two sides, pressing for 60min at 190 ℃ in a hot press, and naturally cooling to obtain the copper-clad plate with the thickness of about 1.0 mm. The performance test method of the copper-clad plate is shown in table 1, and the main performance of the copper-clad plate obtained in the embodiment is shown in table 3. In the table, all the performances of the copper-clad plate meet the requirements of IPC4101/128, and the use requirements of the halogen-free flame-retardant FR-4 copper-clad plate are met.
Example 8: preparation of degradable halogen-free flame-retardant FR-4 copper-clad plate sample
(1) Preparing degradable epoxy resin glue solution: weighing 20g of bisphenol A type liquid epoxy resin E54(EEW 0.53-0.54 eq./100g), 10g of trifunctional epoxy resin XY636(EEW 0.69-0.71 eq./100g), 80g of isocyanate modified epoxy (EEW 0.34-0.40 eq./100g), 90g of phosphorus-containing epoxy resin (P content is 2%, EEW 0.37-0.42 eq./100g) and 65.3g C curing agent (AEW1.26N-H eq./100g), adding a proper amount of methyl ethyl ketone as a solvent, and dissolving and mixing uniformly; then 0.88g of silane coupling agent KH560 and 88.4g of molten SiO were added2Adding 21.6g of SPB-100 phosphazene flame retardant and 5.30gUR-200 curing accelerator into micro powder (D505-10 mu m), and stirring for 30min by using a high-speed dispersion machine to obtain a glue solution with the solid content S/C being about 60%; gel time S/G of gel liquid at 171 ℃: 280-320 sec.
(2) Preparation of resin prepreg: soaking 7628 glass cloth in the prepared glue solution, baking for 10min at 150 ℃ in an oven to obtain a prepreg with the glue content R/C being about 45%, wherein the gel time P/G of the prepreg glue powder at 171 ℃ is as follows: 140-160 sec.
(3) Preparing a copper-clad plate: and (3) overlapping more than 5 prepared resin prepregs, covering copper foils (1OzHTE copper foils) on two sides, pressing for 60min at 190 ℃ in a hot press, and naturally cooling to obtain the copper-clad plate with the thickness of about 1.0 mm. The performance test method of the copper-clad plate is shown in table 1, and the main performance of the copper-clad plate obtained in the embodiment is shown in table 3. In the table, all the performances of the copper-clad plate meet the requirements of IPC4101/128, and the use requirements of the halogen-free flame-retardant FR-4 copper-clad plate are met.
Example 9: preparation of degradable halogen-free flame-retardant FR-4 copper-clad plate sample
(1) Preparing degradable epoxy resin glue solution: 40g of bisphenol A type liquid epoxy resin E54 (E)0.53-0.54 eq./100g of EW), 80g of isocyanate modified epoxy (EEW 0.34-0.40 eq./100g), 80g of phosphorus-containing epoxy resin (P content is 2.5%, EEW 0.22-0.24 eq./100g), 69.9g B curing agent (AEW0.99N-H eq./100g), adding a proper amount of DMF as a solvent, and dissolving and mixing uniformly; then 0.90g of silane coupling agent KH560 and 90.0g of molten SiO were added2Micro powder (D505-10 μm), and stirring for 30min by using a high-speed dispersion machine to obtain a glue solution with the solid content S/C of about 60%; gel time S/G of gel liquid at 171 ℃: 300-340 sec.
(2) Preparation of resin prepreg: soaking 7628 glass cloth in the prepared glue solution, baking for 10min at 150 ℃ in an oven to obtain a prepreg with the glue content R/C being about 45%, wherein the gel time P/G of the prepreg glue powder at 171 ℃ is as follows: 150-170 sec.
(3) Preparing a copper-clad plate: and (3) overlapping more than 5 prepared resin prepregs, covering copper foils (1OzHTE copper foils) on two sides, pressing for 60min at 180 ℃ in a hot press, and naturally cooling to obtain the copper-clad plate with the thickness of about 1.0 mm. The performance test method of the copper-clad plate is shown in table 1, and the main performance of the copper-clad plate obtained in the embodiment is shown in table 3. In the table, all the performances of the copper-clad plate meet the requirements of IPC4101/128, and the use requirements of the halogen-free flame-retardant FR-4 copper-clad plate are met.
Example 10: preparation of degradable halogen-free flame-retardant FR-4 copper-clad plate sample
(1) Preparing degradable epoxy resin glue solution: weighing 40g of bisphenol A type liquid epoxy resin E54(EEW 0.53-0.54 eq./100g), 80g of isocyanate modified epoxy (EEW 0.34-0.40 eq./100g), 80g of phosphorus-containing epoxy resin (P content is 2.5%, EEW 0.22-0.24 eq./100g), 54.7g C curing agent (AEW1.26N-H eq./100g), 20g of trimethylolpropane triglycidyl ether (EEW 0.68-0.74 eq./100g), and heating at 70 ℃ for uniform mixing; then 0.85g of silane coupling agent KH560 and 84.9g of molten SiO were added2Micro powder (D505-10 mu m), then adding 5.09g of UR-200 curing accelerator, and stirring for 30min by adopting a high-speed dispersion machine to prepare glue solution; gel time S/G of gel liquid at 171 ℃: 280-320 sec.
(2) Preparation of resin prepreg: soaking 7628 glass cloth in the prepared glue solution at 70 ℃, then baking for 10min in an oven at 150 ℃ to obtain a prepreg with the glue content R/C being about 45%, wherein the gel time P/G of the prepreg glue powder at 171 ℃ is as follows: 140-160 sec.
(3) Preparing a copper-clad plate: and (3) overlapping more than 5 prepared resin prepregs, covering copper foils (1OzHTE copper foils) on two sides, pressing for 60min at 180 ℃ in a hot press, and naturally cooling to obtain the copper-clad plate with the thickness of about 1.0 mm. The performance test method of the copper-clad plate is shown in table 1, and the main performance of the copper-clad plate obtained in the embodiment is shown in table 3. In the table, all the performances of the copper-clad plate meet the requirements of IPC4101/128, and the use requirements of the halogen-free flame-retardant FR-4 copper-clad plate are met.
TABLE 1
TABLE 2
TABLE 3
Example 11: preparation of glass fiber curing sheet
(1) Preparing degradable epoxy resin glue solution: 40g of bisphenol A type liquid epoxy resin E54(EEW 0.53-0.54 eq./100g) and 80g of isocyanate modified epoxy (EEW)0.34 to 0.40 eq/100 g), 80g of phosphorus-containing epoxy resin (the P content is 2.5 percent, EEW is 0.22 to 0.24 eq/100 g), 54.7g C curing agent (AEW1.26N-H eq/100 g), adding a proper amount of DMF as a solvent, and dissolving and mixing uniformly; then 0.85g of silane coupling agent KH560 and 84.9g of molten SiO were added2Micro powder (D505-10 mu m), adding 5.09g of UR-200 curing accelerator, and stirring for 30min by a high-speed dispersion machine to obtain a glue solution with the solid content S/C being about 60%; gel time S/G of gel liquid at 171 ℃: 280-320 sec.
(2) Preparation of resin prepreg: soaking 7628 glass cloth in the prepared glue solution, baking for 10min at 150 ℃ in an oven to obtain a prepreg with the glue content R/C being about 45%, wherein the gel time P/G of the prepreg glue powder at 171 ℃ is as follows: 140-160 sec.
(3) Preparing a glass fiber curing sheet: and (3) overlapping more than 5 prepared resin prepregs, pressing for 60min at 180 ℃ in a hot press, and naturally cooling to obtain the glass fiber solidified sheet.
Example 12: degradation of copper clad laminate
Adding 1g of the copper-clad plate sample in the embodiment 1, 5 ml of concentrated hydrochloric acid and 95 ml of ethylene glycol into a 250 ml three-neck flask, stirring and heating to 160 ℃, cooling to 100 ℃ after 6 hours, filtering while hot, separating the copper foil and the glass fiber from the degradation solution, neutralizing the degradation solution with 5% of sodium hydroxide solution, separating out a solid, filtering, washing the solid with water, and drying to obtain 0.96 g of thermosetting epoxy resin degradation product, copper foil and glass fiber, wherein the mass recovery rate is 96%.
Example 13: degradation of copper clad laminate
Adding 1g of the copper-clad plate sample in the embodiment 1, 10 ml of concentrated hydrochloric acid and 90 ml of ethylene glycol into a 250 ml three-neck flask, stirring and heating to 160 ℃, cooling to 100 ℃ after 6 hours, filtering while hot, separating the copper foil and the glass fiber from the degradation solution, neutralizing the degradation solution with 10% of sodium hydroxide solution, separating out a solid, filtering, washing the solid with water, and drying to obtain 0.95 g of thermosetting epoxy resin degradation product, copper foil and glass fiber, wherein the mass recovery rate is 95%.
Example 14: degradation of copper clad laminate
Adding 1g of the copper-clad plate sample in the embodiment 2, 5 ml of concentrated hydrochloric acid and 95 ml of ethylene glycol into a 250 ml three-neck flask, stirring and heating to 140 ℃, cooling to 100 ℃ after 4 hours, filtering while hot, separating the copper foil and the glass fiber from the degradation solution, neutralizing the degradation solution with 5% of sodium hydroxide solution, separating out a solid, filtering, washing the solid with water, and drying to obtain 0.95 g of thermosetting epoxy resin degradation product, copper foil and glass fiber, wherein the mass recovery rate is 95%.
Example 15: degradation of copper clad laminate
Adding 1g of the copper-clad plate sample in the embodiment 2, 5 ml of concentrated hydrochloric acid and 95 ml of octanol into a 250 ml three-neck flask, stirring and heating to 155 ℃, cooling to 100 ℃ after 4 hours, filtering while hot, separating the copper foil and the glass fiber from the degradation solution, neutralizing the degradation solution with 5% of sodium hydroxide solution, separating out a solid, filtering, washing the solid with water, and drying to obtain 0.96 g of thermosetting epoxy resin degradation product, copper foil and glass fiber, wherein the mass recovery rate is 96%.
Example 16: degradation of copper clad laminate
Adding 1g of the copper-clad plate sample in the embodiment 3, 5 ml of concentrated hydrochloric acid and 95 ml of heptanol into a 250 ml three-neck flask, stirring and heating to 155 ℃, cooling to 100 ℃ after 4 hours, filtering while hot, separating the copper foil and the glass fiber from the degradation solution, neutralizing the degradation solution with 20% of sodium hydroxide solution, separating out a solid, filtering, washing the solid with water, and drying to obtain 0.95 g of thermosetting epoxy resin degradation product, copper foil and glass fiber, wherein the mass recovery rate is 95%.
Example 17: degradation of copper clad laminate
Adding 1g of the copper-clad plate sample in the embodiment 3, 5 ml of concentrated hydrochloric acid and 95 ml of ethylene glycol into a 250 ml three-neck flask, stirring and heating to 160 ℃, cooling to 100 ℃ after 4 hours, filtering while hot, separating the copper foil and the glass fiber from the degradation solution, neutralizing the degradation solution with 20% of sodium hydroxide solution, separating out a solid, filtering, washing the solid with water, and drying to obtain 0.95 g of thermosetting epoxy resin degradation product, copper foil and glass fiber, wherein the mass recovery rate is 95%.
Example 18: degradation of glass fiber cured sheet
In a 250 ml three-neck flask, 1g of the glass fiber solidified sheet in the example 11, 5 ml of concentrated hydrochloric acid and 95 ml of ethylene glycol are added, stirred and heated to 160 ℃, cooled to 100 ℃ after 3 hours, filtered while hot, the glass fiber is separated from the degradation solution, the degradation solution is neutralized by 20% sodium hydroxide solution, solid is separated out, filtered, washed by water and dried to obtain 0.95 g of thermosetting epoxy resin degradation product and glass fiber, and the mass recovery rate is 95%.
Example 19: demonstration of degradation of copper-clad plate
The copper clad laminate sample strip of example 3, 10 ml of concentrated hydrochloric acid and 90 ml of ethylene glycol were added to a 500 ml beaker, stirred and heated to 145 ℃ and after 1 hour the copper foil was partially separated, and a white glass fiber cloth was seen, see the partial degradation schematic diagram shown in fig. 1.
Example 20: copper-clad plate sample acid etching
(1) The copper-clad plate sample test strip in the example 9 and 100 ml of acid copper chloride etching solution are added into a 500 ml beaker, the temperature is heated to 50 ℃, the copper foil is completely etched after 5min, and the copper-clad plate substrate is found to be smooth and flat without copper scrap residue after the sample is washed and dried by clean water.
Example 21: copper-clad plate sample alkaline etching
The copper-clad plate sample test strip in the example 9 and 100 ml of alkaline copper chloride etching solution are added into a 500 ml beaker, the temperature is heated to 50 ℃, the copper foil is completely coated after 5min, and after the sample is washed by clean water and dried, the copper-clad plate substrate is smooth and flat and has no copper scrap residue.
Example 22: 4-layer PCB (printed Circuit Board) circuit board sample manufacturing method
(1) Example 9 the degradable epoxy resin glue solution prepared in step (1) is impregnated into 7628 glass cloth, and then baked in an oven phase at 150 ℃ for 10min to prepare a prepreg with a glue content R/C of about 43%, wherein the gel time P/G of the prepreg glue solution at 171 ℃ is as follows: 150-170 sec.
(2) And (2) overlapping 7 semi-cured films prepared in the step (1), covering copper foils (1Oz HTE copper foils) on two sides, pressing for 60min at 180 ℃ in a hot press, and naturally cooling to obtain the copper-clad plate with the thickness of about 1.3 mm.
(3) Example 9 the degradable epoxy resin glue solution prepared in step (1) is impregnated into 1080 glass cloth, and then baked in an oven phase at 150 ℃ for 10min to prepare a prepreg with a glue content R/C of about 64%, wherein the gel time P/G of the prepreg glue solution at 171 ℃ is as follows: 150-170 sec.
(4) Cutting the copper-clad plate sample prepared in the step (2) and the semi-cured film prepared in the step (3) into a size of 416mm by 518mm, and sending the cut sample to a PCB (printed circuit board) production line to be processed into a four-layer PCB, wherein the specific processing steps are as follows by combining the steps shown in figure 2:
(a) preparing an inner layer circuit pattern from a cut copper-clad plate sample by adopting an inner layer dry film method through a plurality of processes such as inner layer film pasting, exposure and development, inner layer etching (acid etching process) and film stripping;
(b) performing brown oxidation treatment on the sample plate of the prepared graphic circuit, then taking a prepreg and a copper foil to be overlapped according to a lower overlapping structure, and after overlapping, sending the prepreg and the copper foil to a vacuum press for hot pressing for 60min under the conditions of 2.5Mpa and 180 ℃ to obtain a 4-layer plate with the thickness of 1.5 mm;
(c) mechanically drilling a 4-layer plate sample, oxidizing an epoxy cured substance by potassium permanganate in a NaOH solution to remove residual dirt in the drilled hole to enable the hole wall to be smooth and tidy, and then plating copper to enable the through hole to be metallized;
(d) carrying out pattern electroplating on the 4-layer plate by adopting a normal outer layer dry film, electroplating copper and tin, then carrying out alkaline etching and film stripping, and stripping tin to obtain an outer layer pattern circuit;
(e) and (3) carrying out resistance welding, character milling, appearance milling, testing and chemical tin deposition on the four-layer board sample with the circuit prepared to obtain a 4-layer PCB circuit board sample.